Hi Nauman - there is nothing unusual about the activity you reported - - but without the raw data (i.e. assay type, delta A and volume used) we can't verify your calculations. That said - try a known dilution of your solution, recalc your activity and see if they agree. It's not uncommon to have enzyme activity in mU/mL to kU/mL - - depends on the assay and concentration of enzyme. Hope this helps??